Exergy analysis of steel production processes

Continuous increase of the annual amount of steel scrap generated presents a problem to the sustainability of human society. The effective utilization of scrap is a serious problem to be solved in the near future. and the optimization of the global system of steel production should be considered from various viewpoints, particularly those of environmental load and material efficiency, For the consideration of a global system that contains many different kinds of flow, a criterion for evaluating the efficiency of the system is necessary for optimizing the utilization of materials in the system. The concept of exergy was adopted in this study and the application of exergy analysis to the evaluation of a complicated system was considered. A simulation model was developed for the steel industry in Japan and the exergy analysis of the Blast Furnace-LD converter (BF-LD) process and the Electric Arc Furnace (EF) process was conducted, The exergy loss was expressed as a function of parameters, such as the mixing rate of pig iron in the EF process and the total exergy loss in the system was calculated, The applicability of exergy as a criterion for the analysis of a production process and for evaluating material efficiency was discussed.